Well screen with reinforced plastic rope wrap



J. D. BROWN 3,385,373

WELL SCREEN WITH REINFORCED PLASTIC ROPE WRAP May 28, 1968 Filed Oct. 27, 1966 JAMES D. BROWN ATTORNEYS United States Patent 3,385,373 WELL SCREEN WITH REINFORCED PLASTIC ROPE WRAP James D. Brown, 12429 Kathryn, Houston, Tex. 77015 Filed Oct. 27, 1966, Ser. No. 589,863 Claims. (Cl. 166-232) The present invention relates to improvements in well screens.

In various types of wells such as oil, gas, and water wells, it is desirable to exclude fine sand particles which may be present in or about the producing formation from the well string that is inserted in the well bore and through which the desired liquids or fluids flow to the earths surface. In order to accomplish this function, various types of devices commonly called screens have been heretofore employed.

Generally speaking, such screens are formed by wrapping wire or placing rings of metal about the foraminate d or perforated pipe and are spaced apart a predetermined distance to inhibit the flow of sand particles therethrough and into the perforated pipe but accommodating the flow of the desired well fluids. This type of well screen is not only extremely expensive to manufacture, but due to the fact that dissimilar metals are ordinarily used in forming the screen, electrolysis occurs which, over a period of time, renders the well screen ineffective or useless for the purpose for which it is intended.

Accordingly, one of the objects of the present invention is to provide a well screen of relatively simple construction which overcomes these and other problems presently encountered in well screens and to provide a well screen which will withstand the adverse effects of electrolysis.

Other objects and advantages of the present invention will become more readily apparent from a consideration of the following description and drawings wherein:

FIG. 1 is a broken elevational view illustrating a portion of a well screen with the present invention incorporated therein;

FIG. 2 is a sectional view on the line 22 of FIG. 1 illustrating in greater detail the arrangement of one form of the present invention;

FIG. 3 is an enlarged view of a portion of the well screen of FIG. 1 to better illustrate details of construction of the well screen;

FIG. 4 is a sectional view similar to FIG. 2 but illustrating the material used to form the well screen being positioned on metal pipe;

FIG. 5 is a sectional view on the line 55 of FIG. 3 showing the preferred embodiment of the material which is wrapped on a foraminated tubular core to form the well screen of the present invention; and

FIG. 6 is a sectional view on the line 6-6 of FIG. 3 to illustrate the preferred manner in which the rows of wrapping on the tubular core of the well screen may be spaced to provide access for fluid flow therethrough.

Attention is first directed to FIG. 1 of the drawings wherein a well screen is referred to generally by the numeral 10 and is shown as including a foraminated tubular core 11 having at each end thereof suitable means such as the threads 12 and 13 for connection with a well string whereby it may be lowered into a well bore and positioned at the desired depth so that fluids may pass therethrough and into the well string with which the Well screen 10 is connected and then to the earths surface.

In FIG. 2, it will be noted that the tubular core 11 is formed of plastic such as, by way of example only, polyvinylchloride. In FIG. 4, the tubular core 11 is shown as being formed of ordinary metal pipe such as commonly employed in Well screens. The foraminations 'in the foraminated tubular core 11 are in the form of perforations or openings 14 which may be arranged in any suitable manner in the foraminated tubular core 11, and as illustrated in FIG. 1 of the drawings, such openings are shown as being arranged in longitudinally extending rows with the openings 14 of one row being staggered relative to the openings 14- of an adjacent row.

Spacer means referred to generally by the numeral 15 are provided on the external periphery of the for-aminated core 11, and in the preferred embodiment of the pres nt invention, such spacer means 14 include a plurality of circumferentially spaced and longitiudinally extending strips 16 of plastic material which has a core of metal therein to provide reinforcing as will be described in greater detail hereinafter.

The strips 16 are cut to a desired length and positioned on the tubular core 11 and retained in position thereon by any suitable adhesive such as methyl ethyl ketone or any other suitable adhesive to retain the circumferentially spaced strips 16 in position as the outer layer referred to generally by the numeral 18 is positioned thereon. The spacer means 15 is arranged between the rows of openings or perforations 14 as shown in the drawings so as not to interfere with the flow of fluid from the producing formation through the well sceen 10 and into the well string with which it is connected; however, such spacer means serves to provide a support for the outer wrap 18 and spaces the outer wrap from the external periphery 19 of the tubular core 11 to aid in fluid flow through the well screen 10 and into the pipe with which it is connected.

As illustrated in FIGS. 2 and 4, can be seen that the spacer means 15 provides a space 20 between the outer wrap 18 and the external periphery or surface 19 of the tubular core which provides less resistance to flow from desired formation into the well string.

Attention is now directed to FIGS. 5 and 6 of the drawings wherein the preferred form of the outer wrap 18 is shown, and it will be noted in FIG. 5 that in crosssection the outer wrap 18 is generally trapezoidal in shape and is provided with a core 23 of metal therein to provide reinforcing and inhibit breaking of the plastic 24 from which the wrap 18 is formed. The wrap 18 may be positioned on the spacer means 16 by starting at one end of the well screen and moving circumferentially thereabout to form a row as illustrated at 25 in FIG. 1 of the drawings. If desired, a suitable adhesive as shown at 26 may be provided on the inner edge 24a of the plastic rope 24 to aid in initially positioning and retaining the plastic rope 24 in place as the well screen is formed.

In order to space the rows 25 as illustrated in FIG. 3 of the drawings relative to each other to provide a space 27 for fluid flow between each row 25, an indentation 28 may be formed on the inner edge of the plastic rope 24 as it is formed, such indentation in turn forming the hump 29 as shown in FIG. 6 of the drawings and as shown in the enlarged view of FIG. 3.

It will be noted that the indentations 28 are provided at spaced circumferential points along the inner edge of the plastic 24 so that a plurality of rows of projections 29 extend longitudinally of the well screen 10. The size of the hump 29 determines the space 27 between each of the rows 25, and it can be appreciated that the hump 29 formed by the indentation can be of any desired size to obtain the desired spacing between each of the rows 25.

Thus, the plastic rope 24 is continuously wrapped around the foramin-ated tubular core 11 to form a well screen 10 of a desired longitudinal extent, and as previously noted, the adhesive 26 may be used to retain the plastic rope in position on the spacer means as the screen is being formed and thereafter it will retain its position.

To further aid in retaining the ends of the plastic rope 24 in its final position and to aid in protecting the well screen as it is lowered into the well bore, suitable means such as the cup-shaped members 35 and 36 may be placed at each end of the wire rope 24, such end being indicated in dotted line at 37 and the cup-shaped members 35 and 36 secured in position by suitable means such as .the adhesive similar to that referred to previously herein.

In some situations, it may be preferable to form the rows 25 of individual rings of plastic and then place them over one end of the foraminated core 11 to form the rows 25 rather than use a continuous strip of plastic rope as described in connection with the present invention.

By referring to FIG. 3, it can be appreciated that the present invention is as readily adaptable to well screens presently in use as well as to well screens wherein the foraminated tubular member 11 is formed of plastic as illustrated in FIG. 2 of the drawings. In this event, the circumferentially spaced rows 16 of the spacer means may be formed of strips of the reinforced plastic rope 24 which is also used to form the outer wrap 18 in a manner as heretofore described, and the manner of placing the plastic rope 24 on the ordinary metal pipe of FIG. 4 is similar to that as described with regard to its manner of application to plastic pipe. Openings or perforations 14 are shown as being arranged in rows in the metal pipe illustrated in FIG. 4 ina manner similar to that shown in FIG. 1 in connection with the plastic pipe.

From the foregoing description, it. can be appreciated that since the outer wrap 18 is formed of plastic and since the strips 16 forming the spacer means 15 between the outer surface or periphery 21 of the foraminated tubular core 11 and wrap 18 is also formed of plastic, electrolysis or deterioration of a well screen by electrolysis is eliminated.

Also, the manner of fabrication of the present invention is such that it can be produced more economically than well screens heretofore produced and presently in use.

Since the rope 24 is shaped so that its outer edge 24b is wider than its inner edge 24a, it can be appreciated that the opening or space 27 between adjacent rows is smallest adjacent the outer edges 2411. This inhibits clogging of the screen since any particles small enough to pass between the rows 25 at their outer edge will pass on into the production well pipe.

Broadly, the present invention relates to a well screen employing an outer wrap being formed of plastic rope having therein a core of reinforcing material such as metal to inhibit breakage of the plastic wrap as it is applied in the forming of a well screen.

What is claimed is:

1. In a well screen having a foraminated tubular core with means at each end thereof for connecting to a string of well pipe, the invention including:

(a) means extending about the outer periphery of the formainated tubular core for aiding in filtering fluid flow thereinto, said means including:

(1) spacer means mounted on the outer periphery of the foraminated tubular core; and

(2) a plastic rope, having a metallic core serving as reinforcing, wrapped over said spacer means to form a plurality of rows on the foraminated tubular member, said plastic rope having projections formed in one edge thereof abutting the adjacent row and thereby spacing each row longitudinally of said foraminated tubular member.

2. The invention of claim 1 including means adjacent each end of said rows and extending radially outwardly relative thereto to aid in protecting said plastic as it is lowered into the well bore.

3. The invention of claim 1 wherein said spacer means is formed of longitudinally extending strips of plastic rope having a metallic core, said strips being spaced circumferentially of the foraminated tubular core.

4. The invention of claim 1 wherein the foraminated tubular core is formed of plastic and said spacer means and plastic rope are retained in position thereon by an adhesive.

5. The invention of claim 1 wherein said plastic rope is generally trapezoidal in cross-section so that it is Wider at its outer edge than it is at its inner edge so that the smallest clearance between adjacent rows is along the outer surface of said rows to aid in inhibiting clogging of the well screen.

References Cited UNITED STATES PATENTS 2,081,190 5/1937 Wilson 166--233 3,221,819 12/1965 Dickinson et a1. 166-233 3,234,723 2/1966 Brown 166-242 X FOREIGN PATENTS 1,064,482 12/ 3 France.

CHARLES E. OCONNELL, Primary Examiner. I. A. CALVERT, Assistant Examiner. 

1. IN A WELL SCREEN HAVING A FORAMINATED TUBULAR CORE WITH MEANS AT EACH END THEREOF FOR CONNECTING TO A STRING OF WELL PIPE, THE INVENTION INCLUDING: (A) MEANS EXTENDING ABOUT THE OUTER PERIPHERY OF THE FORAMINATED TUBULAR CORE FOR AIDING IN FILTERING FLUID FLOW THEREINTO, SAID MEANS INCLUDING: (1) SPACER MEANS MOUNTED ON THE OUTER PERIPHERY OF THE FORAMINATED TUBULAR CORE; AND (2) A PLASTIC ROPE, HAVING A METALLIC CORE SERVING AS REINFORCING, WRAPPED OVER SAID SPACER MEANS TO FORM A PLURALITY OF ROWS ON THE FORAMINATED TUBULAR MEMBER, SAID PLASTIC ROPE HAVING PROJECTIONS FORMED IN ONE EDGE THEREOF ABUTTING THE ADJACENT ROW AND THEREBY SPACING EACH ROW 